Cosmetic kaolin-containing preparation

ABSTRACT

The invention involves a cosmetic preparation containing kaolin which may be employed as a mask, lotion, gel or cream with a non-sticky, non-plasticized consistency and with a content of white kaolin with a high proportion of kaolinite and spherical inorganic particles of a particle size of less than 5 μm, with a proportion of spherical particles in the kaolin mixture of 0.5 to 10% by weight as well as a cosmetic skin care composition, in which the proportion of the kaolin/spherical particle mixture falls within the range of over 2 to 65% by weight of the composition as a whole. The viscosity of the composition with the proportion of kaolin/spherical particles is around 2000 to over 15,000 cps higher than a similar composition with kaolin only and without spherical particles, with the difference in viscosity increasing with the proportion of kaolin/spherical particles. 
     The new, pleasantly soft preparation with an inhibitive effect with regard to inflammation permits high kaolin contents to be used to especially good effect in masks and gels.

This application is a 371 of PCT/DE95/01801 filed Dec. 6, 1995 publishedas WO96/17588 Jun. 13, 1996.

The invention pertains to new preparations containing kaolin which maybe employed in cosmetics in the form of emulsions or gels.

It is known that inflammation may be inhibited to a degree through theaddition of kaolin to certain dermatological preparations. Previously,kaolin additives of up to 2% by weight were possible while maintaining aconsistently pleasant sensation on the skin; the emulsion tended to clotseverely above this limit. The addition of a greater proportion also ledto the dulling of the emulsion, an effect that cannot be tolerated incosmetics.

Substrates in platelet form of a certain size, e.g. of zeolite, mica orglass, containing a proportion of spherical particles for the preventionof agglomeration are known from EP-B-406657. A composite powder coatedwith aluminum metasilicate which may also contain kaolin and which hasimproved adsorption properties is known from U.S. Pat. No. 5,182,103.

The objective of this invention is the development of new cosmeticpreparations which, in addition to their skin care effects, provide anincreased inhibitive effect with regard to inflammation as well asproviding a particularly pleasant sensation on the skin.

According to the invention, the cosmetic preparation containing kaolinconsists of

(a) a mixture of white kaolin with a high degree of kaolinite,preferably over 85% by weight, in particular over 95% by weight,modified with spherical inorganic particles with a particle size of lessthan 5 μm in a proportion of 0.5 to 10 by weight of the kaolin mixtureand

(b) a cosmetic skin care composition of the emulsion and emulsion basegroup for lotions, creams and masks; gels and gel bases for lotions,creams and masks in which the proportion of the kaolin/sphericalparticle mixture, based on the overall composition, is in the range ofover 2 to 65% by weight; and in which the viscosity of the overallcomposition including the proportion of kaolin/spherical particlesremain under that of the same composition with kaolin but withoutspherical particles by 2000 to over 15,000 cps and in which thedifference in viscosity increases with the proportion ofkaolin/spherical particles.

A further characteristic of the invention is that the cosmeticpreparations mentioned above provide a particularly pleasant sensationon the skin and have a non-sticky, non-plasticized consistency.

Kaolin mixtures with a proportion of spherical particles of 0.5 to 5% byweight are particularly favorable. In addition, it is advantageous ifthe size of the spherical particles is in the range of 0.1 to 3 μm,especially in the range of 0.1 to 1 μm.

The proportion of modified kaolin mixture (kaolin/spherical particles)is usable in the entire range from approx. 2 to approx. 65% by weight;it is particularly favorable if the proportion of the modified kaolinmixture lies in the range from 5 to 30% by weight, although still higherproportions are possible, especially in powders.

Surprisingly, not only can an improvement of the agglomeration withinthe kaolin suspension be achieved through the formulation of a kaolinmixture with a low proportion of spherical inorganic particles such asamorphous silicon dioxide, but the introduction of kaolin in cosmeticcompositions such as emulsions becomes possible in such high proportionsas would not have been expected by a specialist. The employed kaolin,with a platelet diameter in the range of 0.2 to 1 μm, does not form asuperordinate macrostructure with the roughly equally-sized SiO₂particles, thus avoiding the known condition of plasticity of clays andresulting in a lower viscous dispersion as opposed to the usual mixturesof kaolin and aqueous cosmetic additives, which lead to mixtures withsigns of plasticity.

A further synergistic effect is the hitherto unachieved sensation ofsoftness of the complete preparation on the skin; the cosmetic effect ofcomparable products is surpassed and a significant inhibitive effectwith regard to inflammation is simultaneously achieved.

An additional surprising effect may be observed with gels, in that theaddition of modified kaolin to a gel mixture of only 2.5 to 3% stronglyreduces its stickiness and significantly improves the spreadingcharacteristics of certain gels. The scope of application of gels incosmetics is thus widened.

The viscosity of the cosmetic formulations according to the invention,e.g. as a cosmetic mask, is around 2000 cps lower with a proportion of2.5% by weight of the kaolin/spherical particle mixture as opposed tothe same mixture without the spherical particles; at 30% by weight,about 15,000 cps lower and at 45% by weight significantly more than15,000 cps lower. The measurements were performed with a BrookfieldRVT/DVII viscometer with the C, D, E and F hydrometers. With the Fhydrometer, the viscosity of the mixture with pure kaolin withoutspherical particles at 45% by weight was over 65,000 cps and no longermeasurable, whereas with the kaolin/spherical particle mixture (45% byweight), it amounted to about 52,000 cps.

It may be advantageous for compositions according to the invention to becontained in conventional liposomes or--more favorably--in asymmetriclamellar aggregates, in which these aggregates consist of phospholipidsand oxygen-charged fluorocarbon or fluorocarbon mixture with afluorocarbon content in the range of 0.2 to 100% by weight/volume, thephospholipids have a phosphatidylcholine content of over 30 to 99% byweight and in which the skin penetration of these aggregates isdependent upon the critical solubility temperature of fluorocarbons.

In addition, the aggregates may also be present in the cosmeticpreparation charged with oxygen only.

These aggregates are oxygen carriers and permit the penetration ofoxygen into the skin, thus improving the oxygen supply of the skin. Theproduction of these aggregates is accomplished by the high-pressurehomogenization of phospholipids such as soya lecithin or egg lecithin,synthetic phospholipids or partially hydrogenated phospholipids with aphosphatidylcholine content of over 30 to 99% by weight withperfluorinated or highly fluorinated carbon compounds or mixturesthereof which are able to transport gasses such as oxygen or carbondioxide. In addition to phosphatidylcholine, lysolecithins in theconcentration range from 0.1 to 10% by weight and/orelectrically-charged phospholipids such as phosphatidylethanolamine,N-acetylphosphatidylethanolamine or phosphatidic acid in theconcentration range from 0.1 to 30% by weight may be present.

Unlike the known aqueous liposomes (vesicles), thesephospholipid-stabilized aggregates carry hydrophobic fluorocarbonscapable of transporting oxygen in their core. Their boundary-layerstabilization is accomplished primarily through a monolayer with aninverse arrangement, to which a structure of bilayer films is optionallyattached. Because of this peculiarity of their structural arrangement,these novel aggregates are designated as asymmetrical lamellar oxygencarriers. Their unusual colloid chemical stability may be traced back tothe lamellar structure and the surface charge of the aggregates. Thelatter can be traced back to the choice of suitable phospholipids ormixtures thereof of natural as well as of synthetic origin.Phospholipids, especially phosphatidylcholine in the specifiedconcentration range from 30 to 99% in connection with lysolecithins inthe concentration from 0.1 to 10% and/or charged phospholipids in theconcentration range from 0.1 to 30% by weight are primarily responsiblefor the favorable action in this sense. The claimed action of thephospholipids is verified by appropriate negative zeta potentials and bythe measurement of charge densities (on titration with a cationicpolyelectrolyte). The skin penetration in dependence of the criticalsolubility temperature of the selected fluorocarbons or fluorocarbonmixtures is essential for the employment of the fluorocarbon aggregates(for the employment of asymmetrical lamellar aggregates, also refer toDE-B-42 21 255).

The proportion of the aggregates charged with the modified kaolinmixture may be in the range of 5 to 60% by weight of the completepreparation and are favorably located in the range of 10 to 50% byweight, especially in the range of 15 to 30% by weight.

As described earlier, common liposomes may also be used as a transportsystem for the modified kaolin mixture in the preparations according tothe invention. Liposomes are completely closed bilayer lipid membranescontaining an aqueous volume. Liposomes may be unilamellar (with asingle-membrane bilayer) or multilamellar vesicles (onion-likestructures characterized by a multi-membrane bilayer, with eachseparated from the next by an aqueous layer). The bilayer consists oftwo lipid monolayers with a hydrophobic "tail" section and a hydrophile"head" section. The structure of the membrane bilayer is such that thehydrophobic (non-polar) "tails" of the lipid monolayer orient themselvestoward the center of the bilayer, while the hydrophile "heads" orientthemselves toward the aqueous phase.

The production of liposomes using saturated and unsaturated lipids hasbeen described in many patents, as well as their application as atransport system. The introduction of the modified kaolin mixture may beperformed in the usual manner.

Preparations containing kaolin and the products of cautious ultrasonicmaceration and/or high-pressure homogenization of suspensions ordispersions of vegetable cells, bacteria or yeasts are preferableaccording to the invention. Vegetable substances which have beenpreviously used to good advantage in cosmetics, such as chamomile, aloevera, etc. may be employed, as well as products such as the bark of theMexican skin tree, Mimosa tenuiflora, which results in a particularlyanti-inflammatory, oxygen-rich product.

Baker's, brewer's, wine yeast or other yeast types may be employed.

A particularly advantageous maceration product results from the use ofan ultrasonication flow-through cell in accordance with DE 42 41 154, inwhich the synotrode projects by 1/2 to 2/3 of its length into theflow-through cell, the angle of the synotrode in the acousticirradiation vessel is within the range from 80.5° to 88.5°, in that theratio of the extent of immersion of the synotrode (in mm) to theacoustic irradiation volume (in ml) is set to a value within the rangefrom 1:1.1 to 1:20 and in that the ratio of the extent of immersion ofthe synotrode (in mm) to the proportion of solid matter in the medium tobe sonicated (in percent by weight) is within the range from 1:0.02 to1:2.2.

The effect of the favored combination of asymmetric lamellar aggregates,charged with the modified kaolin mixture and the maceration products ofvegetable and yeast cells in a cosmetic preparation according to theinvention is especially pronounced in the maceration of superoxidedismutase-rich yeast which deliver a high content of superoxidedismutase (SOD). As SOD is effective as a trap of radicals in the skinand catalyses the reaction

    2O.sub.2.sup.- +2H.sup.+ →H.sub.2 O.sub.2 +O.sub.2,

it is, per se, an especially favorable component in cosmetic ordermatological preparations. However, other radical traps may be usedwhich are suited to the bonding of free oxygen radicals, such as vitaminE.

Suitable forms of cosmetic preparation are emulsions, preferablycosmetic masks, especially facial masks. For such masks, the content ofmodified kaolin suspension is advantageous in the range from 3 to 30% byweight, preferably 5 to 20% by weight. In addition, the emulsion maycontain the usual components, such as emulsifiers, perfume oils,protective substances and other skin care components.

Gels are favored as well due to their already-mentioned spreadingcharacteristics; in this case the proportion of the modified kaolinpreferably should lie in the range from 5 to 15% by weight.

The kaolin/spherical particle mixture may also be employed in powders aswell as pharmaceutical preparations.

The production of the preparation is generally implemented by themixture of a dispersion of purified white kaolin with a high proportionof kaolinite with a dispersion of spherical inorganic particles atambient temperature. Water is the preferable dispersing agent. Thepreparation is then mixed with the cosmetic skin care composition,insofar as this is available as an emulsion, in an emulsificationmachine.

After the mixture of the kaolin dispersion with the spherical particledispersion, especially a SiO₂ dispersion, the product may be spray-driedand the dried product directly processed into the emulsion or absorbedin liposomes or asymmetrical lamellar aggregates and then processed intothe emulsion.

In the following, the invention shall be described in detail byexamples. All percent figures are by weight.

EXAMPLE 1 Production of Modified Kaolin (1)

30 l of a suspension of 4 kg of white kaolin with a kaolinite content of96% in water/ethyl alcohol is stirred and added to 40 l of a dispersionof 4.5 kg monodisperse silicon dioxide over the course of half an hourand stirred for a further hour. The product is then spray-dried in aconventional spray tower. The result is a product which is suitable fordirect processing in cosmetic products.

EXAMPLE 2 Production of Modified Kaolin (2)

The process is as in example 1, with the exception that a multivalentalcohol such as ethylene glycol is used as a solvent and 3.5 kg ofkaolin are used.

EXAMPLE 3 Cosmetic Mask (1)

5 separate phases are produced which are consecutively mixed, partlyunder intensive homogenization. The phases A to D are processed at anelevated temperature (40° to 70° C.) and phase D processed at the end atambient temperature.

    ______________________________________                                        Phase A                                                                       glyceryl stearate    4.1%                                                     stearic acid         1.8%                                                     cetyl alcohol        1.8%                                                     Phase B                                                                       distilled water      q.s.                                                     carbomer             0.3%                                                     propylene glycol     2.5%                                                     preservative         0.3%                                                     Phase C                                                                       triethanolamine (TEA)                                                                              0.3%                                                     Phase D                                                                       modified kaolin       30%                                                     chamomile active agent complex                                                                       3%                                                     Phase E                                                                       perfume oil          0.5%                                                     ______________________________________                                    

EXAMPLE 4 Cosmetic Gel

The carbomer is homogenized with water; TEA, preservative and themodified kaolin are consecutively added while stirring.

    ______________________________________                                               carbomer 1.0%                                                                 TEA      0.8%                                                                 water    q.s.                                                                 modified kaolin                                                                        2.5%                                                                 preservative                                                                           0.3%                                                          ______________________________________                                    

EXAMPLE 5 Cosmetic Powder

The ingredients listed below are mixed in the order indicated.

    ______________________________________                                        modified kaolin 65%                                                           magnesium stearate                                                                             5%                                                           silk protein    10%                                                           zinc oxide       5%                                                           maize/rice protein                                                                            10%                                                           color           approx. 5%                                                    ______________________________________                                    

EXAMPLE 6 Kaolin-Charged Liposomes

Liposomes charged with modified kaolin (in accordance with examples 1and 2) were produced as follows. A phospholipid is introduced into awater-kaolin suspension, in which the kaolin was produced in accordancewith example 2. After thorough homogenization, ethyl alcohol is stirredin and homogenized further.

    ______________________________________                                               phospholipid                                                                           15%                                                                  modified kaolin                                                                         7%                                                                  water    q.s                                                           ______________________________________                                    

EXAMPLE 7 Kaolin-Charged Aggregates

Asymmetric lamellar aggregates charged with modified kaolin (inaccordance with examples 1 and 2) were produced as follows. Modifiedkaolin is introduced to perfluorodecaline mixed with glycerin andpropylene glycol and thoroughly homogenized. A phospholipid with aphosphatidylcholine content of 50% is stirred into this homogenizedmixture and water added. After thorough homogenization, the aggregatescharged with modified kaolin are ready for further use.

    ______________________________________                                        phospholipid          25%                                                     modified kaolin        4%                                                     fluorocarbon (perfluorodecaline)                                                                    50%                                                     glycerin             3.5%                                                     propylene glycol     5.0%                                                     water                q.s.                                                     ______________________________________                                    

EXAMPLE 8

This is produced as in example 7, with the exception that the proportionof modified kaolin amounted to 10%.

EXAMPLE 9

This is produced as in example 7, with the exception that in addition tothe modified kaolin, macerated bakery yeast in the form of thesupernatant centrifugate produced by the ultrasonification processdescribed above is homogenized into the fluorocarbon mixture.

    ______________________________________                                               phospholipid                                                                            20%                                                                 modified kaolin                                                                          5%                                                                 glycerin  3.5%                                                                propylene glycol                                                                         5%                                                                 yeast maceration                                                                        16%                                                                 perfluorodecaline                                                                       40%                                                          ______________________________________                                    

EXAMPLE 10

This is produced as in example 9, with the exception that a 19.5%proportion of the maceration product of the bark of the Mexican skintree (Mimosa tenuiflora) is added.

EXAMPLE 11 Sunscreen

After the homogenization of phases A and B at an elevated temperature,these are mixed with one another and homogenized thoroughly. Phase C isthen mixed in at about 30° to 40° C.

    ______________________________________                                        Phase A                                                                       sorbitan sesquioleate                                                                              5.0%                                                     cetyl alcohol        4.5%                                                     stearyl alcohol      3.5%                                                     titanium dioxide     3.6%                                                     Phase B                                                                       propylene glycol     2.0%                                                     water                q.s.                                                     glycerin             1.0%                                                     titanium dioxide     1.9%                                                     Phase C                                                                       preservative         0.3%                                                     perfume oil          0.4%                                                     asymmetrical lamellar aggregates                                                                   30.0%                                                    charged with modified kaolin as                                               per example 9                                                                 ______________________________________                                    

EXAMPLES 12 and 13 After Sun Gel

The asymmetrical lamellar aggregates produced as in examples 9 and 10and charged with modified kaolin and a yeast or Mexican skin tree(Mimosa tenuiflora) maceration, as well as perfume oil and preservativeare consecutively stirred into the complete gel at ambient temperature.

    ______________________________________                                        polyacrylic acid (molecular                                                                       1.0%                                                      weight approx. 4,000,000)                                                     hydroxyethyl cellulose                                                                            0.3%                                                      propylene glycol    3.0%                                                      benzoic acid        0.3%                                                      modified kaolin with yeast/                                                                       25.0%                                                     Mimosa tenuiflora maceration in                                               aggregates                                                                    perfume oil         0.3%                                                      preservative        0.3%                                                      water               q.s.                                                      ______________________________________                                    

EXAMPLE 14 Cosmetic Mask (2)

This is produced as in example 3, with the exception that the quantityof modified kaolin amounted to 12%.

EXAMPLE 15 Pharmaceutical Ointment

After homogenization and homogenous blending of the phases A and B at anelevated temperature (approx. 65° C.), phase C is added at 30° to 40° C.

    ______________________________________                                        Phase A                                                                       lanolin              5.0%                                                     cetyl alcohol        2.0%                                                     cetyl alcohol and PEG-40 castor                                                                    3.0%                                                     oil, 1:1                                                                      hexyl laurate        1.5%                                                     Phase B                                                                       water                q.s.                                                     glycerin             2.0%                                                     propyl alcohol       2.0%                                                     modified kaolin       45%                                                     Phase C                                                                       preservative         0.3%                                                     ______________________________________                                    

Comparative Example 1

A cosmetic neck-decollete mask was applied to ten female test persons.Mask A corresponded to the example 14 in accordance with the invention.Mask B contained normal kaolin with a kaolinite content of 97%, in whichthe kaolin content had to be reduced to 8% as a result of processingdifficulties. The evaluation by the test persons was performed on thebasis of the following scale:

1=very pleasant skin sensation;

2=pleasant skin sensation;

3=unpleasant skin sensation;

4=very unpleasant skin sensation.

    ______________________________________                                        Evaluation in Percent                                                                   1   2           3     4                                             ______________________________________                                        Mask A      90    10          0   0                                           Mask B      0     0           80  20                                          ______________________________________                                    

The clear superiority of the mask in accordance with the invention withregard to the sensation on the skin may thus be recognized. A comparisonwith regard to anti-inflammatory effectiveness could not be made due tothe varying kaolin contents.

We claim:
 1. Cosmetic preparation containing kaolin, characterized byits availability as a lotion, mask, cream or gel with a particularlypleasant sensation on the skin and a non-sticky, non-plasticizedconsistency, consisting of a mixture of white kaolin with a highproportion of kaolinite and spherical inorganic particles of silicondioxide or titanium dioxide with a particle size of less than 5 μm and aproportion of spherical particles in the kaolin mixture of 0.5 to 10% byweight, dispersed in an aqueous cosmetic preparation of the emulsion andemulsion base group for lotions, creams and masks as well as gels andgel bases for lotions, creams and masks;the proportion of thekaolin/spherical particle mixture falls within the range of over 2 tomaximally 65% by weight of the composition as a whole; the viscosity ofthe composition with the share of kaolin/spherical particles is at least2,000 cps, preferably 2,000 to 15,000 cps lower than the samecomposition with kaolin only and without spherical particles, with thedifference in viscosity increasing with the proportion ofkaolin/spherical particles.
 2. Cosmetic preparation containing kaolinaccording to claim 1, characterized by the proportion of sphericalparticles of 0.5 to 5% by weight of the kaolin mixture.
 3. Cosmeticpreparation containing kaolin according to claim 1, characterized by thesize of the spherical particles which lies in the range of 0.1 to 3 μm,particularly in the range of 0.1 to 1 μm.
 4. Cosmetic preparationcontaining kaolin according to claim 1, characterized by the proportionof the kaolin/spherical particle mixture which amounts to 5 to 30% byweight.
 5. Cosmetic preparation containing kaolin according to claim 1,characterized by the containment of the kaolin/spherical particlemixture in asymmetric lamellar aggregates consisting of phospholipidsand oxygen-charged fluorocarbon or fluorocarbon mixture in which theproportion of fluorocarbon lies in the range from 0.2 to 100% byweight/volume, with a phosphatidylcholine content of the lipid group of30 to 99% by weight, and in which the aggregates demonstrate skinpenetration dependent on the critical solubility temperature of thefluorocarbons.
 6. Cosmetic preparation containing kaolin according toclaim 5, characterized by the additional content of asymmetric lamellaraggregates charged solely with oxygen in the mixture.
 7. Cosmeticpreparation containing kaolin according to claim 5, characterized inthat the aggregates, in addition to the kaolin/spherical particlemixture, contain a product of the cautious ultrasonification and/orhigh-pressure homogenization of suspensions or dispersions of plantcells, bacteria or yeasts.
 8. Method of using a preparation containingkaolin consisting of a mixture of white kaolin with a high proportion ofkaolinite and spherical inorganic particles of a particle size of lessthan 5 μm, with a proportion of spherical particles in the kaolinmixture of 0.5 to 10% by weight in a cosmetic mask, cosmetic gel orcosmetic cream, in which the proportion of the kaolin/spherical particlemixture lies in the range of 2.5 to 30% by weight of the totalpreparation.